#include <iostream>

using namespace std;

class A
{
public:
    A()
    {
        cout<<"构造函数"<<endl;

    }
    ~A()
    {
        cout<<"析构函数"<<endl;
    }
private:

};
int main()
{
//    A*a1=new A;

    A*a2=(A*)operator new(sizeof(A));
    new(a2) A;

    //delete a1;
    a2->~A();
    operator delete(a2);

}
